The present invention relates to a packaging box for a golf ball, and more particularly to a packaging box which can be decomposed completely when it is disposed into the ground in consideration of environmental protection, looks fine, and is not damaged easily to allow the packaging box to have a high function.
The mode of packaging golf balls to be used in a golf course is different from that of packaging golf balls to be used in a training place. The former golf ball is mostly sold by the dozen or half a dozen at a shop by putting three or four golf balls in an inner box 1 called sleeve and these inner boxes 1 packaged in an outer box 2, as shown in FIG. 4A. More specifically, when the inner box 1 accommodates four golf balls B, three inner boxes 1 are packaged in the outer box 2 to prepare one-dozen box, whereas when the inner box 1 accommodates two golf balls B, three inner boxes 1 are packaged in the outer box 2 to prepare half-a-dozen box. The reason the golf balls are packaged in the inner box is to distinguish the number of golf ball in a golf course, therefore golf balls having the same number are packaged in the same inner box.
The golf ball for the training place is not sold at a shop but delivered to the training place by packaging them in a corrugated cardboard box.
Mostly, inner boxes 1 and outer boxes 2 are composed of paper and a resinous film laminated on the paper to allow them to look fine and reinforce the paper. Polypropylene, polyethylene, and polyvinyl chloride are hitherto used as the resinous film to be laminated on the paper.
As shown in FIG. 4B, some packaging boxes for a golf ball have a window. More specifically, some inner boxes 1 have a window 1a consisting of a transparent resinous film 3 formed on a portion thereof to allow golf balls B accommodated in the inner box 1 to be seen well. The same film as the resinous film laminated on the paper is used for the transparent resinous film 3 and the outer of transparent resinous film 3 is bonded at surrounding of the window.
Normally, the used packaging box for golf ball is burnt as flammable waste. In some cases, it is buried under the ground as waste. In the latter case, the paper is decomposed when it is left in a natural environment, whereas plastics laminated on the paper as the paper-reinforcing material are not decomposed. To bury the undecomposable plastics under the ground pollutes environment, which has become a social problem recently.
Further, the window 1a of the box is covered with the resinous film 3 as same as the resinous film laminated on the paper covers and the resinous film 3 has a low strength. Therefore, when the window 1a is formed straddlingly on two or more planes of the inner box 1, folded lines of the resinous film cannot be formed sharply, which is not preferable in consideration of the appearance of the inner box. Another problem of the conventional packaging box is that during transport of golf balls, golf balls move in some extent in the inner box, thus colliding with the resinous film 3 forming the window 1a. In this case, there is a possibility that the golf balls may damage the resinous film 3. If the window 1a is large, the resinous film 3 forming the window 1a is liable to be damaged. Therefore, the size of the window is limited.
The present invention has been made in view of the above-described problems. Thus, it is an object of the present invention to provide a packaging box, for a golf ball, having an environment-unpolluting decomposable laminate material which forms a harmless substance when it is buried under the ground, can be bent sharply when it is bonded to a window-forming portion of the packaging box, and is not easily damaged when the golf ball collides therewith.
To achieve the object, there is provided a packaging box, for a golf ball, formed by folding a packaging sheet comprising a decomposable laminate material consisting of a polylactic acid-containing polymer film and a paper laminated with the polylactic acid-containing polymer film.
The polylactic acid-containing polymer film is a copolymer of lactic acid obtained by fermenting bacteria of grain starch. The polylactic acid-containing polymer film is biodegradable. Thus when the polylactic acid-containing polymer film is disposed into the ground, natural hydrolysis proceeds in the ground without leaving its original shape. Bacteria forms a product formed by the hydrolysis into a harmless decomposed substance consisting of water and carbon dioxide. Accordingly, the packaging box formed of the packaging sheet having the biodegradable paper combined with the laminate material consisting of the polylactic acid-containing polymer film is decomposable when it is left in the ground and does not pollute environment. When the packaging box is burnt, it does not damage an oven because it is low in its quantity of heat and does not pollute the atmosphere.
The polylactic acid-containing polymer film composing the laminate material is higher than polypropylene and polyethylene hitherto used in strength, rigidity, transparency, and glossiness. Thus, the packaging box, for a golf ball, formed of the packaging sheet having the biodegradable paper laminated with the laminate material consisting of the polylactic acid-containing polymer film is higher than the conventional one in strength. That is, the packaging box does not get out of shape easily and appears fine because of its superior transparency and glossiness.
A portion corresponding to the window is cut out from the paper, and the window is covered with the polylactic acid-containing polymer film laminated on the paper.
In this case, it is unnecessary to bond a separate window-covering film to the paper. The installation of the window-covering film on the paper can be achieved by the operation of laminating the polylactic acid-containing polymer film entirely on the paper. Because the polylactic acid-containing polymer film has a high strength as described above, the golf ball accommodated in the packaging box does not damage the polylactic acid-containing polymer film, when the golf ball collides with the polylactic acid-containing polymer film owing to vibrations of the packaging box during transport thereof. Consequently, the size of the window is not limited, which allows a design to be made as desired. Because the polylactic acid-containing polymer film has a high degree of transparency, it allows the golf ball accommodated in the packaging box to be seen therethrough well from the outside when it is used as the window-covering film. Thus, the polylactic acid-containing polymer film does not hinder the purpose of forming the window on the packaging box.
When the packaging sheet is folded to form a box, the window is formed straddlingly on two or three planes such that the polylactic acid-containing polymer film covering the window is bent perpendicularly at a boundary between the planes adjacent to each other.
When window-covering portion of the polylactic acid-containing polymer is cornered by bending it, it can form a sharp edge at the portion thereof bent perpendicularly because it has a high degree of strength and rigidity. Therefore, the polylactic acid-containing polymer film can enhance the quality of the packaging box.
The polylactic acid-containing polymer film allows the window to be large. That is, the polylactic acid-containing polymer film allows the window to be formed straddlingly on the three planes of the packaging box. In this case, it is easy to bend the window-covering portion of the polylactic acid-containing polymer film perpendicularly at two portions.
Raising processing of forming a fine convex portion on the surface of the packaging sheet can be preferably accomplished. When the packaging sheet is formed as a box, the raising processing is carried out to form the processed portion as the convex portion on the surface of the packaging box. In the raising processing, with the paper laminated with the polylactic acid-containing polymer film, the packaging sheet is pressed with a concave plate and a convex plate disposed above and below the packaging sheet to form the convex portion on the surface thereof.
The polylactic acid-containing polymer film which is used in the present invention is higher in its strength and rigidity than polypropylene, polyethylene, and the like hitherto used as the laminate material. Thus, the paper laminated with the polylactic acid-containing polymer film can follow the shape of convex/concave portions of the concave plate and the convex plate. Therefore, when a fine convex portion is formed by the raising processing, the edge of the convex portion can be formed distinctly, unlike the conventional laminated paper, thus allowing the packaging box to look fine. Another advantage of the polylactic acid-containing polymer film is that it is not marred or damaged when the convex portion is formed.
It is preferable to use the polylactic acid-containing polymer film heat-treated after it is formed by being biaxially drawn to improve its heat-resistant property, strength and rigidity while maintaining its transparency.
A design is printed on the paper. The polylactic acid-containing polymer film is laminated on the printed surface of the paper. The packaging box of the present invention can be preferably used as an inner box for accommodating two to four golf balls therein. A plurality of inner boxes are packaged in an outer box to prepare the outer box containing one dozen of golf balls or half a dozen thereof. Needless to say, it is preferable to form the outer box of a packaging sheet consisting of paper and the polylactic acid-containing polymer film laminated thereon. The polylactic acid-containing polymer film is high in its strength and rigidity. Thus, it is possible to form a window on the outer box as well and cover the window with the polylactic acid-containing polymer film. It is also possible to form the raised portion on the packaging sheet.